Tuft cutting mechanism for axminster looms



p 7, 1948. w. Y. ROBB 2,448,829

TUFT CUTTING MECHANISM FOR AXMINSTER LOOMS Filed Oct. 9, 1947 INVENTOR WALTER X R085 ATTORNEY Patented Sept. 7, 1948 TUFT CUTTING MECHANISM Fon ff.

Y AXMINSTER LOOMS Walter Y. Robb, -Whitinsville, Mass, assignor.

to Crompton & Knowles Loom Works, Worcester, Mass, a corporation of .Massachusetts Application October 9, 1947, Serial No. 718,864

This invention relates to improvements in Axminster loomsand it is the general object of the invention to improve the tuft cuttin mechanism in such manner as to insure continuity of enagement between the two cutting blades throughout the tuft cutting operation.

Axminster looms ordinarily operate with a series of tube frames which are moved one by one to a tuft forming position adjacent to the cloth being woven. After the tuft is formed and the.

tube frame has been raised a slight distance to pull off yarn for the next row of tufts which it will form, cutter blades operate to sever the tufts from the tube frame. These cutter blades are ordinarily mounted on relatively heavy castings which extend across the loom and are operated in timed relation with respect to the tube frame movements to cut the tufts while the tube frame is in its low or tuft forming position. The blades first engage each other at one side of the loom and are then moved in such manner that the point of cutting moves progressively across the loom so that only a few tufts are cut at any instant during the operation.

It is found that the cutting mechanism in Axminster looms of considerable width sometimes fail to cut the tufts because of vibration of one or another of the cutting blades. During this vibration the blades temporarily separate from each other and such tufts as should be cut at that time are either improperly cut or not cut at all. It is an important object of the present invention to provide vibration arresting means for at least one of the knives to brace and reinforce it or-its bar at various points along its length across the loom to insure continuous engagement between the two cutting blades with resultant cutting of all of the yarn tufts.

'In a form of Axminster loom which has one into extended use in recent years, the front knife passes under the back knife and has the effect of lifting and vibrating the latter. The front knife is supported bya bar which can be made relative -ly heavy, but the proportions of the loom are such that it is difficult to make the bar for the back knife of a weight equal to that of the front bar, and it is for this reason that the back knife vibrates. It is a further object of the present invention to provide a series of vibration arresting arms or the like arranged across the loom and so located as to engage the back bar at a plurality of spaced points and prevent it from moving upwardly when the front blade moves under the back blade. These arms are preferably mounted in such manner that they can be ad- 12 Claims. (01. 139-2) lusted vertically to' compensate for anyir-reguprogresses.

larities which may exist in the back knife bar.

They are also preferably resilient and so made as to offer increasing resistance to upward move ment of the back bar as the cutting operation With these and other objects in view which will appear as the description proceeds, my invention resides in the combination and arrangement of parts hereinafter described and set forth. In the accompanying drawingswherein a convenient embodiment of my invention is set forth,

Fig. 1 is a vertical section through the forward part of an Axminster loom showing the front and back knife'bars in tuftcutting relation with the invention operating to prevent upward movement of the back bar, g f

Fig. 2 is a detailed front elevation, parts being broken away, looking in the direction of arrow 2,

Fig. l, and

Fig. 3 is a horizontal section on line 3-3 of Fig. 2.

Referring to Fig. 1, the loomframe I supports a stationary casting l I on which a guide l2 is held in adjusted position by adjusting screw l3. Guide I2 is provided for and guides the front knife bar I-5' along the under rear edge of which is located the front cutter blade [6. The loom frame also supports a stationary back guide I! for a back knife bar l8 along the lower forward edge of which extends the back cutterblade IS. The guides 12 and I1 are inclined toward each other as indicated in Fig. 1, and serve to guide the blades l6 and is toward each other during the cutting operation.

The loom is provided with a cross shaft having an arm 2 I secured thereto the upper part of which is connected to a forwardly extendin link 22 attached to the cutter bar IS. A depending arm 23 secured to shaft 20 is connected to mech anism not shown which rocks shaft 20 in a clock, wise direction during the cutting operation and then rocks in a counterclockwise direction to restore the front knife to its normal forward noncutting position. Similarly, a lever 25 is attached by a link 26 to the back bar l8 and is rocked by mechanism not shown in timed relation with the rocking of shaft 20 to effect forward motion of the back knife blade.

The loom is provided as usual with the pullover shaft 21 around which extend transporting chains one of which is shown at 28. The chains carry a series of tube frames two of which 29 are shown attached to the chains. As the feed sprocket 30 on shaft 21 advances by a step by step motion the tube frames are moved progressively to trans. fer position from which they are moved in a downward direction toward the cloth for the tuft forming operation. In Fig. 1 the tube frame in tuft forming position is indicated at T.

The warp threads W are controlled by harness frames three of 'which'are shown in I, the front and-back frames ba and 34, respe'ctively, being up and the intermediate frame being down. The cloth C is guided over a cloth board 36 which may be of any approved form. l-he mechanism shown in Fig. l is duplicated on "tnecppcsite siue of the 100m.

The loom frame includes in' its construction a relatively large I-beam 40 *which extends across the loom and is supported by brackets one -"of which is shown at 4|. The brackets are secured to the loomsides of the frame and one o'fthe functions of the beam is to give rigidity to"thelo'om. Beam 40 has a vertical web 42 and horizontal flanges 43 the lower of which is bolted at 44 to the support 4i. g I

The matter thus far described is of common construction and operates in the usual manner. Reference maybe had to U. S. Patent to Dacey No. 2,306,304 'for further details of the knife bar guides. While the tube frame T is in the down position shown in Fig. --l the cutting operation will "be performed as already described, after which "the tube frame will be returned to the transporting chains and the sprocket "in will be given-an angular movement to place the next tu-be frame in transfer position. The cutter b la des i6 and t9 have an .cperation-for'each 'dip- 115mg of a tubeframe. In 'Fig. '1 the cutter blades are shown in the vpositionthey occupy-during the cutting operation, the front blade-t6 being-below the back blade 19. I V

As already mentioned, the rear cutter bar I8 is subjected to an upward "force by front *blade 46 during the cutting operation-resulting in-more or less vibration. 'The effect of this vibration when i-t isin a vertical direction is -to-cause temipor'ary separation of the two knives so thatsome So'f the tufts extending from the tube frame are not cor'n'p'lietly severed. In order to prevent this upward vibration of the back cutter bar teas the front knife 4!; passes under the back knife -1 9 I provide a series of vibration arresters -or arms designatedgenrallyat45. Each arm 45 is preferably made of a bent strip of relatively heavy butslightlyresilientsheet steel. The upper part 46 0f each armds-substantially vertical and provided with vertical slots 4'l.- -A forwardly and downwardly extending part be --of the "arm 45 leads to a forwardly curved apart 4!} which also curves over and'downwardly in front of the barness frames- 33 and =34. The lower end =-of arm 45 "is formed with pressure foot Elli to bear against the upper pairtof -the rear knife bar =18. .A reinforcing *rod =51 secured to the drertical part 46 and the curved part 19 may be used if desired to-stiff en the arm 45.

The arms 45 located at the sides of the center of' the *lcem are mounted on supports '55. Each support 55 is preferablyof angle form and has a top horizontal-arm :51 anda vertical front arm 58. Bolts 59 secure the horizontal arm 51 to the top flange 43 of tire I-beam. Bolts 60 extend through web -42, and the upper apart til- 0i arm *45 and vertical arm =58 'and have head-e 61 which draw part- 4G firmlyagain-st the vertical arm '58 when nuts -82 are tightened. Sleeves or collars $3 sm-round'the bolts-60 between webd-Z andarm 56 -to-brace and support the latter.

or foot 66 which is held against the forward edges of flanges 43 by bolts 61, see Fig. 3, which pass through collars 68 similar to collars 63. Bolts 61 also pass through a spacing plate 69 and the 'iipperp'art 46 of the central arm 45. Arm 45 ait th'e c'eh'ter o'fthe loom is thus held in a manner similar to "the other arms 45.

As the-back knife bar moves forwardly while engaging the feet 50 of the several arms 45 it will he -subjected to downward forces exerted by the feet and be restrained from moving upwardly insuch manner as to arrest any vibration in an upward-direction the-effect of which would be to move blade t9 upwardly away from blade l-G. The feet 50 are "of sufficient length to maintain pressing engagement with the backi'kni-fe bar 48 throughout the cutting operation. The feet '50 are'curved downwa'rdly and forwardly,and as the cutting operation proceeds they exert increasing downward forces on the knife bar t8.

Fig. 2 shows three of the brace arms *45,-but 1 nst-limited to this number. Thus, I have shown a single central arm 45 supported at one side only of foot 86, but'the latter is so formed *that it could support a second brace arm if de- "sired.

From the foregoing it will be-seen that I'have provided simple means for preventing upward vibration 'of the back cutterknife bar 18 during the cutting operation as the front blade it :passes under the back blade I 9. The reinforcin'g means comprises a plurality of spaced arms which possess some resilience and 'are formed with pressure feet '58 "which are preferably curved so as to exert increasingfdownward forces'on'bar 4 8 as it moves forwardly. The feet preferably remain in engagement with the back *knife bar 4 8 throughout 'thecuttingoperation. 'It 'will also 'be seen that the upper parts 46 of the arms '45 :are ad instably and firmly secured to 'c'arriers 'mounted'on the I-beamMi.

:Having thus described my invention it will be seen that changes and modifica'tions may be -'made therein by those skilled in the art without departing from thespirit and scope of the invention and I do not wish to be limited 'to the details herein disclosed, but what I claim i-s:

:1. 'Intuft yarn cutting mechanism for' an minster loom, a front cutter bar'exte'ndlngacross the loom and supporting a front cutter blade, a back cutter 'bar extending across the loom and supporting a back cutter blade under which the front blade moves during a tuft cutting operation, the front blade durin said cutting operation exerting an upward force on the back blade tending to raise and vibrate the back cutter 'bar, and means engaging the back bar and exerting a'downward :forc'e thereon during the cutting operation andre'sisting upward movement and *vibration of said back bar and blade.

:2. tuftlyarn 'cutting mechanism foran 'h'xminsterloom, afrontcutter bar extending across the loom and supportinga front cutter Made, a back cutter bar extending across the loom and supporting a'backcutter blade under which the front blade moves 1 during a tuft cutting operaation, the front blade during said cutting operation exerting an upward force on the back blade tending to raise and vibrate the latter, and a plurality of vibration arresters arranged in spaced relation across the loom and exerting downward forces at a plurality of points spaced along the back bar during a tuft cutting operation to resist upward movement and vibration of said back bar.

3. In tuft yarn cutting mechanism for an Axminster loom having a frame, a front cutter bar extending across the loom and supporting a front cutter blade, a back cutter bar extending across the loom and supporting a back cutter blade, one of said blades passing under the other blade during a tuft cutting operation and one of said bars and the corresponding cutter blade tending to vibrate during the tuft cutting operation, and plural means exerting forces on said one bar at spaced points along the length thereof during the tuft cutting operation tending to re-- sist vibration thereof.

4. In tuft yarn cutting mechanism for an Axminster loom having a frame including an I-beam extending across the loom, a front cutter bar extending across the loom and supporting a front cutter blade, a back cutter bar extending across the loom below the I-beam and supporting a back cutter blade under which the front blade moves during a tuft cutting operation, the front blade during said cutting operation exerting an upward force on the back blade tending to raise and vibrate the back cutter bar, and a plurality of vibration arresters arranged along said I-beam and extending downwardly therefrom and engaging said back cutter bar at a plurality of points to resist upward movement and vibration thereof during the cutting operation.

5. In tuft yarn cutting mechanism for an Axminster loom having a frame including an I-beam extending across the loom, a front cutter bar extending across the loom and supporting a front cutter blade, a back cutter bar below the I-beam extending across the loom and supporting a back cutter blade under which the front blade moves during a tuft cutting operation, the front blade during said cutting operation exerting an upward force on the back blade tending to raise and vibrate the back cutter bar, and a plurality of vibration arresters secured to the I-beam at spaced points along the length thereof and extending downwardly therefrom and each having a resilient foot engaging the back bar and exerting a downward force thereon to resist upward movement and vibration of the back cutter bar during a tuft cutting operation.

6. In tuft yarn cutting mechanism for an Axminster loom, a front cutter bar extending across the loom and supporting a front cutter blade, a back bar extending across the loom and supporting a back cutter blade under which the front blade moves due to backward movement of the front bar during a tuft cutting operation, the back bar moving forwardly and the front blade exerting an upward force on the back blade during a cutting operation and tending to raise and vibrate the back cutter bar, and a vibration arrester having a resilient foot engaging said back bar and exerting a downward force thereon which increases as the back bar moves forwardly to resist upward movement and vibration of said back cutter bar.

'7. In tuft yarn cutting mechanism for an Axminster loom having a frame, a front cutter bar extending across the loom and supporting a front cutter blade, a back cutter bar extending across the loom and supporting a back cutter blade under which the front blade moves during a tuft cutting operation and exerts an upward force tending to raise and vibrate said back cutter bar, and a vibration arrester supported on the loom frame above said back cutter bar and having a resilient downwardly and forwardly curved foot engaging the back cutter bar during the cutting operation and resisting upward movement and vibration of said back cutter bar.

8. In tuft yarn cutting mechanism for an Axminster loom having a frame, a front cutter bar extending across the loom and supporting a front cutter blade, a back cutter bar extending across the loom and supporting a back cutter blade under which the front blade moves during a tuft cutting operation and exerts an upward force tending to raise and vibrate said back cutter bar, and a plurality of vibration arresters mounted on said frame and arranged at spaced points across the loom, each vibration arrester having a resilient downwardly and forwardly curved foot engaging said back bar during a cutting operation and resisting upward vibration of said back bar.

9. In tuft yarn cutting mechanism for an Axminster loom having a frame, a front cutter bar extending across the loom and supporting a front cutter blade, a back cutter bar which moves for-- wardly during a cutting operation extending across the loom and supporting a back cutter blade under which the front blade moves during a tuft cutting operation and exerts an upward force tending to raise and vibrate said back outter bar, and a plurality of vibration arresters supported on the loom frame above the back bar and extending downwardly toward the latter, each arrester having a resilient downwardly and forwardly curved foot engaging the top of the back bar and effective to exert a downward force on said back bar which increases as the back bar moves forwardly to resist upward vibration of said back bar.

10. A vibration arrester for the back cutter bar of an Axminster loom which includes in its construction an elongated member above the back bar, said arrest-er having an upper arm to derive support from said member and having a part extending downwardly from said arm and terminating in the forwardly and downwardly extending foot for engagement with the back cutter bar.

1 1. A vibration arrester for the back cutter bar of an Axminst-er m which includes in its construction an elongated member above the back bar, said arrester having an arm to be supported by said member and having a part extending downwardly from said arm and terminating in a forwardly and downwardly curved resilient foot for engagement with the back cutter bar.

12. A vibration arrester for the back cutter bar of an Axminster loom which includes in its construction an elongated member above the back bar, said arrester having an arm to be supported by said member and having a part extending downwardly from said arm and terminating in a forwardly and downwardly curved resilient foot for engagement with the back cutter bar, and a reinforcing member connecting said arm and foot.

WALTER Y. ROBTB. 

